You didn’t say what “spacious” means. How big is your database (size of the file in the Finder), and how big is your thumb drive?
I would recommend cutting back the number of internal Backup folders to 3, as 10 is really overkill, especially because you have limited storage space on which the database resides.
Personally, I’m comfortable with 3 internal Backup folders because I habitually do two things: I use the DT Pro Scripts > Export > Backup Archive script to store the smallest possible, compressed and dated external backup of my database periodically, and especially before I try anything unusual. And I manually trigger Tools > Verify & Repair followed by Tools > Backup & Optimize after investing substantial time and effort in making changes to the database – usually at break time.
I don’t regard Tools > Rebuild Database as a normal or routine procedure. In over 4 years I’ve used Rebuild Database perhaps 3 times, and the last time was probably about 2 years ago. I would recommend a rebuild of an old DT PE database that was created with an early version of DT PE. But Rebuild isn’t required for routine preventive maintenance.
Your thumb drive should be several times the size of your database, to give your database room to ‘sprawl’.
To feel well backed up I would suggest that you periodically run the Backup Archive script and store the compressed backup on the computer you are using at the time. So: you’ve worked on the database at home. Before leaving for the office, run the script and save the archive to your home computer’s drive. If you modify the database at the office, repeat that routine on that computer. As you have a relatively small database (“spacious thumb drive” is a contradiction) this will run very quickly.
Thumb drives (I assume a USB flash drive) are very much less reliable than hard drives, especially if you use them like a hard drive. Which is to say that if you frequently write data to a flash drive, it will “wear out” much faster than a hard drive.
As your database grows, it will probably no longer fit (with needed “extra” space) on your thumb drive. At that point I would switch to carrying the compressed archive of the latest version of the database on the thumb drive. When you move, e.g. to the office computer, copy the archive to your office computer, uncompress it and double-click on it to open it under DT Pro. If you make changes, archive the new version of your database to the thumb drive. And so on.